John s



(NqModeL) J. s. POTTER & 1). J. OARTWR'IGHT- SOCKET FOR INGANDEISGENT ELECTRIC LAMPS- No. 485,587. Patented Nov. 1, 1892.

E EEEE* -ATENT:

FFICE".

JOHN S. POTTER, OF NEWTON, AND DAVID J. OARTWRIGI-IT, OF BOSTON,

MASSACHUSETTS; SAID CARTWVRIGHT ASSIGNOR TO SAID POTTER.

SOCKET FOR INCANDESCENT ELECTRIC LAMPS.

SPECIFICATION forming part of Letters Patent No. 485,587, dated November 1, 1892.

Application filed October 6,1890. Serial No. 367,237. (No model.) 7

To all whom, it may concern.-

Be it known that we, JOHN S. POTTER, of Newton,in the county of Middlesex, and DA- v11) J. CARTWRIGHT, of Boston, in the county of Suffolk, State of Massachusetts, have invented a new and useful Improvement in Sockets for Incandescent Electric Lamps, of which the following, taken in connection with the accompanying drawings, is a specification.

The object of this invention is the production of a socket for incandescent electric lamps, which socket can be safely used in damp places Without injury to the insulation and which will firmly hold the lamp and afford perfect electrical contact of the terminals of the conducting-wires within the socket. A socket having for its object theprevention of injury to the insulation by moisture has been in use for some years; but in this de vice the terminals of the connecting-wires within the socket are cemented to the socket and are thus liable to become so loosened by variations of temperature and other causes as to cease to afford a firm and sure contact of the terminals with the terminals of the conducting-wires in the sockets.

It is the object of our invention to obtain a contact which will always be firm and reliable.

To this end the invention consists in the combination, substantially as and for the purpose set forth, with a block of porcelain orany other suitable insulating material impervious to moisture, provided with recesses at opposite ends separated by a partition, of contacts connected to the conducting-wires and attached, mechanically, to the partition in the socket in such a manner that a firm and reliable contact is insured.

In the accompanying drawings are shown devices which embody the principle'of our invention.

- Figure l is a sectional view of a socket adapted to receive a Thomson-Houston incandescent lamp, Fig. 2 being a plan view of the same, Fig. 3 being a sectional view of a socket Referring to the drawings, A is a block of porcelain or other insulating material which is impervious to moisture and made in the form of a frustum of a cone.

B is a deep recess in the wider part of the frustum, which recess receives the base of the lamp.

C is a shallow recess in the narrower part of the frustum, and this recess contains a filling of insulating Waterproof cement, which holds the conducting-wires in position and also prevents the access of moisture to the socket.

D is the partition which separates the two recesses. For the reason that the block is generally formed by molding or casting this partition forms part of the block and is of the same material. When the block is of glass or porcelain, it is obvious that metallic contacts cannot be readily screwed to the partition for the reason that screw-threads cannot be formed in it. We therefore make use of a block of hard rubber or other similar insulating material capable of holding a screw, and this block of insulating material E is placed in the recess B, which receives the base of the lamp and is clamped and firmly fixed to the partition D by means of a screw G, which passes from the other recess through a perforation in the partition and is tapped into a block of insulating material. A washer a may be placed between the head of the screw G and the partition D. This block E does not fill the recess; but the space between the walls of the recess and the block is filled with a suitable waterproof cement of insulating material, which is poured into the recess B and flows into the'recess 0 through the perforations in the partition, through which the conductingwires H and K pass. Slots may be formed on the block across the bottom of the same and in the side for the purpose of allowing the cement to flow around the block, and thus more effectually prevent the entrance of moisture. The cement is used solely for this purpose, the block being sufficiently held by the screw G. To this block are attached the metallic contacts which form the terminals of the conducting-wires, and when the baseof the lamp is placed in the recess B establish electrical contact with the terminals of the In the Thomson-Houston lamp one'of the'ter minals is formed by a metal socket in the base of the lamp, which socket has an inter nal screw-thread, and the other terminal is formed by aring of metal insulated from this" socket, but surrounding the same on the bottom of the base of the lamps. The contacts on the block E may be such as would be adapted for either form of lamp, as shown in Figs. 1 and 2 and Figs. 3 and 4. In Fig.1 we have shown a ring F, of metal, fixed in" the block E and connected with one of theconduct ing-wires H, and a central metallic screw 1; in diameter equal to the socket in the baseof the Thomson-Houston lamp and having a screw-thread thereon which fits the internal screw-thread on the socket, said screw or pin I being fixed to the block E and insulated from the ring F. To this screw or pin I is electrically connected the conducting-wire K; 1 Instead of a ring one or more metal pieces V In the fc'rins shown in Figs 3 and at a sir'nilarc'entral screw or pin I may be used, and a shell L, of metal, 5

wire andadapted to makeelectrical contact 1 with thetilainent terminal contacts in the center of the base of thelamp,a filling of cement of a waterproof insulating material around 1 the conductors in the other recess.

may be fixed to the block.

having a screwth read adapted receive the base of theEdison lamp, se'cnred td the block, and this shellis electrically cennected to the conducting-wire H. The ring F may be preserved and the shell may be suitably secured to the ring by metallic statesman-s: as, for example, metallic screws. By the addition of this shell the same socket which has been used to hold a Thomson-Houston lamp may be used tohold an Edison lamp; This is an advantage in electrical installation: The conducting-Wire's H and K are (revered with insulating material and embedded in the insulatingcement above referred to.

In case the partition is" made of scine insterial which is capable of holding sc'i c"vvas, for examplawhat is known as duralite thecontacts could bedirect'lysecnred tethe partition; butwe regard porcelain or other vitreous material as the best material fer the purpose,'in which ca'sethe blcck E will here" quired for the attachment of the socket-ten n lv a, i

l-I avin thus described onr inventicn, what we clai n, and desire to secure by Letters Pat ent of the" United States, is 4 1. The combination, substantially and or-th purpq iifdrthtbf block o ihsuv lating material i pervi us to moistnre, ree w l pn ite ends 9f th s lb i, of the recesses being adapted to receive the base of an incandescent electric lamp and ne other recess having the conducting-wires cemented thereima metallic contact in the recess which adapted to make electrical contact with the filament terminal contact on the base of the lamp, and a filling of a cement of a Waterproof insulating material around the conductors' on the other recess.

2. The combination, substantially as and for the purpose set forth, of a block of insulating material impervious to moisture, recesses in opposite ends of the block, separated by a partition, one of the recesses being adapted to receive the base of the lamp and the otherrecess having the conducting-wires cemented on it bya waterproof insulating material, a block of hard rubb'er or other similar' insulating material capable of holding a screw placed in the recess which receives the lam p and clamped to thepartition by ascrew or screws, metallic contacts fixed to this block,

electrically connected to one of the conductin g-w'ires, and adapted to make electrical con tact with one of the filament terminals on the lamp, a metallic contact fixed in this block, insulated from the other contacts and electrically connected to the other condiictingccmbinatidn, substantially asand for the par-pose set forth, of the block A, of

porcelain onother' insulating material, impervious to moisture, recesses B and Q in oppo-' s'lite ends of the block, separated by a par-ti tion, the block E, of hard riibber or other similat" insulating material, capableof holding a sci-eve placed in the recess B and firmly clamped to the pa'rtition by a screw or screws passing through the partition, the metallic r'ingr, fixed o the face or the block E,tl'1e condncting-wire' H, electrically connected to this ring and passing throiigh this partition, the central metallic pin I, need in the block E and projecting into therecess B, the conducting-wire K, electrically connected to the pin, and the cement of waterproof insulating material between the block E and the walls of the recess B and in the recess (3.

In testimony whereof We have signed diir names to this specificatiomin the presence of two siibscribing witnesses, on this 2d day of October, A. D.'1 S90; 0

J S; Y O'lTER- a A a, y DAVID J. OARTWRIGI-IT. Witnesses; .I. ILBENNETT,

ALEX; L. HAYEs; 

